Pneumatic action.



A. JOHNSON, A. C. SWANSON & A. H. UTTERBERG.

PNEUMATIC ACTION.

APPLICATION men not. 23, I916.

Patented July 30, 1918,

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UNITED STATES PATENT OFFICE.

ALFRED JOHNSON, ARTHUR o. swAnsoN, AND ALFRED H. nr'rnnnnne, orcIIIoAoo,

ILLINOIS.

PNEUMATIC ACTION.

Specification of Letters Patent.

Patented July so, 1918.

Application filed October 23, 1916. Serial No. 127,066.

To all whom it may concern:

Be it known that we, ALFRED JOHNSON and ARTHUR C. SwANsoN, both citizensof the United States, and ALFRED H. UTTER- BERG, a subject of the Kingof Sweden, residents of Chicago, in the county of Cook and State ofIllinois, have invented certain new and useful Improvements in PneumaticActions, of which the following is a specification.

Our invention relates to selfplaying musical instruments, andparticularly to improve pneumatic action therefor.

The object of our invention is to simplify and improve the constructionandarrange ment' of the valve mechanism for controlling the operation ofthe action pneumatics to reduce the cost of manufacture and to makeinspection and repairs easier.

011 the accompanying drawings a structure is shown embodying thefeatures of our invention. In these drawings- Figure 1 is a plan view ofa-pneumatic action unit,

Fig.2 is a sectional view on plane 2-2, Fig. 1,

Fig. 3 is a plan view with the top cover removed and the valve seatsupporting flexible member swung back to reveal the construction in thediaphragm chamber,

gral therewith. A plate 12 is hinged at its "rear end to the bottom ofthe body at one end thereof and extends below the body and the extension11, fiexible'fabric 13 being secured to the plate 12 and to the body 10and its extension 11 to form the action bellows. The block 10 is boredvertically to leave the annular slot 1 1. aroundthe platform 15 whosetopis below the'top of thejblock to leave the space 16 abovethediaphragm 17 i which issecuredat its periphery to the rim of theplatform, the platform being ,hol-

lowed out to provide the space 18 below the diaphragm and the centralpocket- 19. Surrounding the upper end of thespac'e .16 is the depressedannular-seat20 fora metal valve disk 21, a sealing washer 22 beingpreferably applied between the disk and seat. The disk has the centralopening 23 forming a passageway between the space 16 and the valvechamber 2 1 in the cover 25 secured to the block 10 by screws 26, apassageway 27 in the cover connecting the valve chamber with thepassageway 28 leading to the interior of the action bellows. Above thevalve chamber 2A the cover 25 has the atmosphere port 29. l

The ports 23 and 29 are controlled by a valve 1) whose movement iscontrolled by the diaphragm 17 and atmospheric pressure. Theconstruction of the valve forms an important feature of our invention.It comprises a disk 30 preferably of wood which has a plurality of guidelegs 31 extending downwardly therefrom, these legs extending through theport 23 to guide the valve as it is moved upwardly and downwardly duringoperation of the action.

rectly by the diaphragm when the diaphragm is forced upwardly, butpreferably an ad ustable abutment is provided for the These guide legscan be of sufiicient lengthto be engaged didiaphragm. As shown, a screw32 threads phragm, the diaphragm having preferably a stiff remforcingabutmentdisk 35 secured to its upper. face. The top of the disk 30 istenedto receive a tool for turning the screw 7 to ad ust its head withreference to the dia-' faced by a layer 36 preferably of leather for yinsuring air-tight engagementof the valve around the air port 29 whenthe valve is up. Betweenthe cover 25 and the body 10 we interpose asheet 37 of soft flexible material preferably leather, this sheetextending over the metal valve disk 21 and has the central opening inregister with the opening 23 of the disk. The sheet 37 formsa sealingseat for the valve '0 around the opening or port 23, and the sheet isalso compressed between the body-1O and cover 25 to form a seal betweenthe chamber 16 and the valve chamber 2 1 when the valve is down.Preferablyv also the metal :valvedisk 21 issupported on the flexiblesheet 37 by being glued thereto-so that when the cover 25 is removed thesheet with the valve seat thereon can be readily removed to give accessto the diaphragm. To insure proper receiving of the valve seat disk thesheet is glued to the top of the body at the outer end thereof, asindicated at 38. Then when the cover 25 is removed and the valve 1;withdrawn, the sheet can be swung back, as indicated in Fig. 3, toexpose the upper diaphragm chamber and the diaphragm.

Extending through the block 10 from the central pocket 19 below thediaphragm is a pipe 39 which in practice extends into one ofthepassageways in the vacuum chest to be connected with one of the openingsin the tracker board of the instrument. Passageways 10 through the block10 extend from the upper diaphragm chamber 16 to the block end tocommunicate with openings in the vacuum chest leading to the interiorthereof. Normally the spaces above and below the diaphragm are under lowpressure by being connected with the vacuum compartment of the vacuumchest, atmospheric pressure then acting on the valve 1) through the port29 to hold the valve open with the head of the screw 32 against thediaphragm.

When the valve is down the interior of the action pneumatic 13 isconnected with atmosphere. As a music sheet travels over the trackerboard and an opening thereof comes into registration with the trackerboard opening, air under atmospheric pressure will rush into space 19below the dia phragm, the space above the diaphragm still being subjectto low pressure, the result being that the diaphragm is thrown upwardlyto raise the valve to close the atmosphere port 29 andto connect theaction pneumatic 13 through the now open port 23 with the space 16 abovethe diaphragm and the vacuum space with the vacuum chest so that theplate 12 of the action pneumatic will be swung upwardly. As shown, thisplate has the usual extension 4E0 provided with a slot 12f0r receivingthe lower end ofa striker rod. When the tracker board opening is againclosed the pressure below the diaphragm is reduced to that above thediaphragm by virtue of the usual bleed passageway between the vacuumcompartment of the vacuum chest and the atmospheric passageway to thespace below the diaphragm, the valve being then shifted back to itslower position to close the port 23 and to reopen the atmosphere port 29to the action pneumatic.

g The structure of the valve 1) is'extremely simple, a block of woodbeing turned and "cut to leave the disk 30 and the guide legs 81. .Bymeans of the screw 32 passing through thedisk 30 the valve may be readily adjusted in relation to the diaphragm.

/ and atmosphere inlet.

Only the top of the valve is faced with leather, the leather sheet 87forming a seat for the lower face of the valve. The section ot the sheetabove the chamber 16 is held in horizontal alinement by the seat disk 21which is glued thereto and which is supported on the annular seat 20surrounding the chamber 16. The sheet being hinged at one end to theblock 10 by being glued thereto assures accurate seating of the disk 21after it has been swung away from its seat with the sheet.

l/Ve do not, of course, desire to be limited to the exact constructionand arrangement sh Wn, as changes are no doubt possible which wouldstill come within the scope of the invention.

We claim as follows: 7

1. In pneumatic action mechanism of the class described, the combinationof a block having a diaphragm chamber, a diaphragm mounted in saidchamber, an annular seat formed in said block above the diaphragmchamber, a metallic plate mounted on said seat and having a port abovethe diaphragm, a cover for the block having a valve chamber over saidport and having an atmosphere passageway leading thereto, a sheet offlexible material clamped between said cover and block and having anopening in register with said port, and a valve in said valve chamberseating on said sheet and having guide legs extending through said porttoward the diaphragm, said valve being actuated by the diaphragm tocontrol said port 2. In pneumatic controlling mechanism of the classdescribed, the combination of a block having a diaphragm chamber, adiaphragm mounted in said chamber, a cover on said block having a valvechamber therein and having an atmosphere inlet to said chamber, a sheetof flexible material clamped between the block and cover, a stifi' platesecured to the under side of said sheet to fit over the diaphragmchamber, said sheet and plate having a port 'therethrough between thevalve chamber and the diaphragm chamber, and a valve in said valvechamber having legs extendingdownwardly through on said block having avalve chamber therein and having an atmosphere inlet to said chamber, asheet'offlexible material clamped between the block and'cove'r, a stiflplate secured to the under side of said sheet to fit over the diaphragmchamber, said sheetand plate vhaving a 'port therethrough between thevalve chamber and the diaphragm chamber, and a valve in said valvechamber having legs extending downwardly through said port to thediaphragm, said sheet forming a flexible sealing seat for the lower faceof said valve, said sheet being glued to the block along one end wherebyit may be swung to carry said plate away from the ALFRED JOHNSON. ARTHURC. SWVANSON. ALFRED H. UTTERBERG.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G."

